SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e57994af06e4c87dd333a7c5c39518684e87d4fe78d18d9cb0730e5b8d046ac' 
  AND token = 'bCa1vwIFpX5ahSMeKKgDzimkYDzaId28UhZiPc9aKOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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