SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17b6a4f08e57c276ce76c77a74624eb9a5075f7e02e4767f9dfef9db8cfb583e' 
  AND token = '/oS1IOOey/PIUxfpuSoivBNa/RNBJxlCeFUvQjdbXwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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