SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116651296db885e30e9a589a9c45c91f4af2757aa215345b609f62f9c9157807' 
  AND token = 'POwQyHNgl2RvoAMoRY7hp4GVNat4hwDIEpLkldRiPWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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