SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72867e03a62040f64b5db93c40a953af6d22bc62bdfb53833e666f2170885b05' 
  AND token = 'uLwlc4VQm3d29JyVZ4X1m0USXceiEUDk6UK+Wzgwc60=' 
  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"
    }
  }
}