SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28118cf4376a376b9b4c131ae1332f73ddc68cd44c1b625685fc94b51ccfc954' 
  AND token = 'uv6b/cpA6rMMKDmjdZpHje5Qg07MJcZ+ukFLh8qsSI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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