SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd8f4ace0fb4db08fd4448edb11d6232510cc027cfeef2848b611ba484507611' 
  AND token = 'afXbFXfTdPmMDXVAukDj2Ksw7v3Hk7gtPBkPh9RcHCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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