SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ab0a57f5e0d5b52bdbc6c96baf283781c2fef7425200a10a57bb3273b46997' 
  AND token = 'iT6jCTYtqgY/gjPaIZQBvpppAYpMKC4r0BMNomKzrCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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