SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e00edda4ded9a878958909aee0c48878a475063ec47bede9a72764f6eacc2268' 
  AND token = 'ZD5tYYsJZJvVyypLy50rqGbwe+IF26dbAZBjYUyrfDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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