SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a41ee46dde40abd28d2564a86d065e8c0708616e0fe3586fb1cd19a9f0c2877' 
  AND token = 'GgbWhaPoQPj25Achnw1sIyLTR6V96QRbJX7DY2Mqcrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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