SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '847759706eb025c66827f1a9f89d83b92f4ba2fdc2ed40dfdd46697927647ee9' 
  AND token = 'W5amqJITGtPShAPFP7Rg+JNmBGK2Ee/pGxBE5gkBnOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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