SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f48859b80c382769e43632a1cdfc69971b1af94c73ac11f50d7752430bdf8cf7' 
  AND token = 'hX0eL2U3Icf0qvRjmSCCpVrF+OBuej8w5sK85d8NFGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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