SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '126d017cf1381228ef4ea408b29fba8500c78decf63d5a49458ac8a3bc7f9e26' 
  AND token = '2CbK5CY/OZsS6vzjG/RN1g287aOtuEHWfJOqswsmfyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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