SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbe044708df4594e75cd3e66e542484a175a3c8a1f04755abf6fa992c1f9416' 
  AND token = 'xCNwd2HXbVCfzXYysaxCjPyHMfS/UlyK7a96kQ2NO/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}