SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f665160f0f72571d6e95534497fb04ab49fc605ef0ce428b6508b573fc1a8b' 
  AND token = 'j7mEn7eLwcox9APIUT3WNwRAkqSS+5WqNvhz0Zrc3kQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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