SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64226db2cf0a9f5b83038788d523ee521dd317548f6c9817453e2c39ad8a726c' 
  AND token = 'bAAVp2foFhQdSkhNYRAZJlGfKFwq2aBd0NvUIEh2Uk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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