SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e2c1bc6fc37134c5efde7318aad43354e69cfb2ba228e56076dc79334f81a01' 
  AND token = 'gp5F7zThTxa3W3DhJwxvgQJqdV/lQXGqb8Oi4UD8PtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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