SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e2b97e8ab06aae359915da794dffcdcca8fa99d174f086b47213ce58e053f0' 
  AND token = 'KqSYK0DIBdGG3mzlYqQ7EPgrHr52BCaaHSZRejYTFqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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