SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '876b90b491741b18da78eb158069dda92a91396b80ba2d7e34e79c9ae0cb2bb1' 
  AND token = 'CkBb/9yTY1u8TFwZB+ZXicwV2r8ODFCQ4IbaGWpHbtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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