SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6982d3250c7a1fbf619c6f9cc054cc757bd6e94e8916728e798189f147695cfc' 
  AND token = 'N340ssgiBb3BEOizOwBmSB1WPrwHUG+ryl36zu2BMdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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