SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40480fcf0a2d18d73844583c07807d1afaf35e9cb1d922af6c42eda2b6e0f8e8' 
  AND token = 'QHVc+yqHXC8Gz5JYpHSyId6Kt7QNxKBqy8rz8x/ykJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}