SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2baec9ca8e0eb2b32cde7567b9c3459ba4222e616dd46de08d03f2194cce3da7' 
  AND token = 'fazEczEm4DXBcIMdXpWUA8oabShuO2pEmCTIlFXiGJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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