SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f13d2fa8c2a658eba4423aec14112a1e2342c64e5c867bf54c702cf912f17a' 
  AND token = 'YCvVxdXsxNtf4DoXxv3w/2mKR9BbvloG+RIAmxazFu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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