SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655affa92449804ce53b8c8efa570ef9b857a283fa041a7a5df6e6d168ca561a' 
  AND token = '2Jj4Y/grhXpJ/PPxEkV4hjU6FE+UOcCNIGtlnVNboOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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