SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2eb203c219167bc21d80460a6a8f887fcc018fc676601987d6863ea1d6dc353' 
  AND token = 'hE9C9lkVFrxxsw/aqhuyQIOHJVZKuZ+S1kWO5ixkJuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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