SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893118f66a4473cad20f2052190240b48ce10a62a4160db07649e2995bf2e4f0' 
  AND token = 'OG+yZo1uHAao8v6RZhfTLbhcUzcPuimJRNEN0yxrBmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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