SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e451dc4b47a427abefd6585ea56c5da1662269aa034426056212362b30e0be6d' 
  AND token = 'FyVGgf/kwsFUuoiHsILjwzIuJUrVse9oM6+kheNZ3Ig=' 
  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"
    }
  }
}