SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb02b9fbaf172c8b61f72541df31c3d27bb5625ae22316cf300e296065a1a9f8' 
  AND token = 'jkBHMZGmKVu1zKwbqWtOFE/ZiOH84TkI3Xv6Oh5T2LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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