SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c51248ec7e2bf211cc87fd182b59163eca456ba66dc659759e7dd25e4462b2' 
  AND token = 'oX6I+SfscnJwa9FjwLdQ8AAYqOS7+ubb1BdXRUVQmOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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