SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b07efa0bd4ac4dd347d1f0054b0753742fc1973723b6f4991e19ae7e2eb114fc' 
  AND token = 'YrEAUUPSQZqmHVhR1z3HjRK+hLbjca4QyWV30Q6Ulkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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