SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a75149595e290b4a63a5f3dd35bfcf32869f7571698c80641464669c5aa8af4f' 
  AND token = '6nXaDPLTTCBN/OHShd8z/rk0oxnNSu990RDr9KqXvHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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