SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0ba80d43474474e189dc783b69d4595f57371eec6d353a02e562d7601a512d2' 
  AND token = 'KcYMUjh7pu868ZrQX2+mDPIuVYRWaNZ5q8YCQeZ2Fl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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