SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67f301f601e35d74d57ef57e7bf1d978ca4f09e89a351401ec5aa91cc3d20db5' 
  AND token = 'QvOqU2GhZCWTBwQBg9R3oCbh+0AMpz6NX680UJNF/Dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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