SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '223364f418459122f869c5458e273c77aa21cbb3f8cafd8b91f4098ac3ef2bfa' 
  AND token = 'GTGeLA1jmrhZvRmbNPJPpaoqPJaYheHNWzsVgf5ggFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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