SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '162890830109cff152a47fe5cb47e774e0acaed27d0e1185b8ca126754817a91' 
  AND token = 'cl/8lmU9dRkZHSNUjqB/mH1FFxMMo578EpZPJJH8xPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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