SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a668acbc928d44905668b4a209a438e815d5b0099cb26799cf68b1c16e2e19e' 
  AND token = 'LsH4JxNJEKrsLGS/6MILW6jeDlzFz3lVJHhlcoHb4wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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