SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237fa9be19f795be5365ba99842093cff68fcf03048021e08e139e2b0b545883' 
  AND token = 'aEoG+b7zsWOJu/oeJLAg1IVklZmN29zCyxzrJIXevUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}