SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ca60993912fbffc315203d60fb33e0ddc9c47551077f8adf5d933fa08178bdf' 
  AND token = '4RWpkUk2nF5MVb9anXOWFarRF6FbKksB3OJUdANWwrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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