SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc3471af5c5271ccd63a1ab2523d4506fff20685598fdd5dfac9c956b270ef77' 
  AND token = 'hP0ajJujIbZLDf3ZEnUPuwj1e+P5RzNNoYxQBRMMcF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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