SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c23be2fdd25dde7335de7b84865507f9a787d4c7ac8f91376e745f6a09c079d' 
  AND token = 'Ky2qioLaM59lbdObQ0NkMejA+5Vprtw+THkrZeti5Bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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