SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a1db684759a4fcf3f67d7e37c4df4b2aa8fd08fa22e595b0383f0b16d26f54a' 
  AND token = 'qho3AQkvmMgkfQoylbVKUlrvqVSRGO8PTQ1bzJGA/mU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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