SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73d1f1545b0f14532c74e1f7ff767f5e87aa575d82a87eec683b7af37aa0748f' 
  AND token = 'S0dXPupvXyaZMfFdej20Ti+hDH9JiGQq/6NUOW6kWtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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