SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2e1446d10337876a63d74572f3512ccaa4248a9a0366c1bd17009f942671b04e' 
  AND token = 'YCDtltKTG1ZT4Ap0AalqDsph4jyhkWFoycV2zXSBLIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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