SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14f0c194cf9c9f8e7ce76588b38e7d17a04b64050efb1d7301131361a0fa42bd' 
  AND token = 'OdvJbvDg7twAF3hLp1ky6KKJ6ZBMiHuG6CmABYIxeuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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