SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33d0019328c5fb75a771dbd11847e11a36d55a1fadb8780aaa93f66183148a03' 
  AND token = 'qVDSS99RQbVwNQGeLVaiq3cVHhhm/Dd+FRvYirBDD4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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