SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1961b9eb4a383ce6a71da755292415acdf3ef5bf0f9cc409d5c6f2a6197cab39' 
  AND token = 'NrkrRnothVlL7QVhoIZ4XYzQAaHGAo4mJUrJD61C7+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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