SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b88268ca6b577f2b852ab09ca488443bbe32bab4a760050ca27d41494b9adaf3' 
  AND token = 'JVneWgB23R+wokHJMZI/g2a+l+HGxwCK6OidifFHfCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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