SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5112774a8996d3b4c42654922ade62694af4c0038f736b51053632f3c8b6ac19' 
  AND token = 'zqbSxl5mce4jb08OMI2HImhOFDyrrOMton4488YHnhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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