SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf685c5f8d7862f867afd7fa1b273e15d5bd1e5f035f106e523448f5e61f3c5' 
  AND token = 'apSXRZM2rpRsV1mH/hoCFqAIp5ZI3i3AWdhPN3qpwmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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