SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6460041381a313601a2fe52848f223f9dea88454fc8e4bda6384f993c479ea48' 
  AND token = 'yik8atT77Fw5aO7lm3Stzg4KhiVhcfF+gCzbFmlirXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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