SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ccb358c57e7831d85c2c73d34a94c5dca541dcd543595496f20fd2ec5004184' 
  AND token = 'sSI7yvVBe1eROpihlVuf4hMSX1zBkYM42LsXrRWz55M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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