SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45ffd33cbbe86e4e83ae6ad1f0e72901c9d4c3309e74ceea9eea11e6d354524f' 
  AND token = 'xn/qfywH4zRwb8eNtJomdhDsQz03qXXzMcnZ0CQdffo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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