SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a622d1453f7a648a0831fb2aa947ab9444ac0e4ab45ed29252bfa18343e424d' 
  AND token = '41NyT5g8uvpZwUa5SpdReWAkVZgqLb4RrNi+ruZJC+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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