SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3637ab50c38c79863babee06a093c532a34630532e20da81373df9b0b5e0b73' 
  AND token = 'rh4NjRyhBYYJG6NzT19TntEo/pu5mvozKOq6LQ/SXMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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