SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2050e7bab3b1a6d125447990bdb229fbe55c8a2f2a4a258290b0f7e753414250' 
  AND token = 'KpcSoWVoIoahOdzPQZPA+jnMLavRRiCFgaKtVdvnaKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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