SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '578acb77613946518441103c3bebbd2e54428b59753f189d00c563e1f0db28f9' 
  AND token = 'uO00+vMuFYeLEL8Yt33LGDZ9KjG4S0aCvyHHTJ/6o7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}