SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbe0ad6345917b9640bc5c9aed0271fdde49757915b13f76c02e7e8efa6c963' 
  AND token = 'NmecRZ7FdP71hojZQCfJTm/wWUAIxwwviZmnGdrUTaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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