SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '483a3fc4b7a00862d596520b40b310429499c969be83b1eef85b592eb6b34df2' 
  AND token = 'ODO4ofHqcV5erJUAwaLEVey5uVxAihWZ0KU8KI1Te4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}