SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8be32c4280dd0f47210a84f92922f3e95ad9e8f2fcb4da027e5237c6a42f9dda' 
  AND token = 'xSZ8u9LL1IS/MytD5+smJptdEuhFMEbptn7SEN/5DG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}