SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57b093a3226b752f634e00413541285b91592af19df5b2b4667896c36ecc95c5' 
  AND token = 'SCgmtNWZdXMAJv4HsvRD+pgQPfvG3R5Op3iYW2l3Ojg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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