SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f9713a5c9f00d535067361b44a157223f9ff4cfeb9386baaf766d178d2664ac' 
  AND token = 'toemoQCxakGOOj5G5ajtjbP2dZwrEVvGNKGS7kfKWS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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