SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461f4318942b3128d20bfebea93647511ffa69bbc3006022cfd196b5d7c4168e' 
  AND token = 'I2aPsl5ZwEu20+LiQcMCmfAxCQl6hoQoN4RAqV06GGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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