SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e3f5bbee7a0912dfcb73510c73f0cf3dfd7f8fc6c242ce6d5f04f03d47e58a0' 
  AND token = 'Cq0rF0BOVMnOaItgu7nbN5v747qv7EG1Tcry3kWUL48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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