SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a0df282878fda8c82b18e4d5e509fb6f82f01f915440a92e3ec3aeb354aba80' 
  AND token = 'v9sDJikOQwGsq1a4OV9QuI96PdgM35wLREQedSvsWU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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