SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f628333f03d2b26f0eeaec15593f2704c2686802144017e53644117bb443d786' 
  AND token = 'CYp7L1EYvjOvT2SOyRx9epKkJDjkuP0lCUXV7irFcyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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