SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '269cced798239b80d7f6db6ffba9758086fe00689da57f8e6ae8a59ac570b64e' 
  AND token = 'LApWIZs/8AnVab3nyL4NFJAQjVMvK3ZpF2jHs2sWmwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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