SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca7bb0aeb01cf1b8b15082836850f777a4662c3e70ea01043e6573c137e3592' 
  AND token = 'bVS7WzIMcKYshn72evlkubr0yrpSEbtRqzNT0O5wvLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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