SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e10aaa363f051994b63f1b52bcf9a66b6f25b07a711946b617ae43db52fbd43' 
  AND token = 'sEVP5R+3lkdPvgzvwFqO88rAKuymSsRNws/ynvHjt0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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