SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da841e93d57fc356cbbcfff282ec4d16e77e12bf52313ea46d3d2405ae91c4cd' 
  AND token = 'NhQOe0yjfDxMu2W6Lut1Q7Wyk2JLJ4TJpf09r3n+oXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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