SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03cd6cb14de66aff140b122dbe4e8fdea445e65ab03d4e5abd46574fd311695f' 
  AND token = 'hc15cJCpc9O3p76oeoFla1Do+zBatWOlVEenUsWYCBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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