SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92d815553beb6bbe86a99c26e6ed3d47563e9255377ed4da609cf604f1269dc1' 
  AND token = 'NBvtpV0QNKygwHHTOIMRxWBTV1bWmxSjamPfnbS6QU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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