SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c724e5ef64247ca9365b6d49e636c06d8cb2beb8130194c2ef31320c7652ccb6' 
  AND token = 'AVrFW2766kV4Kv9nLa9qCPwWgBMtUYJuOnUBq29eqXc=' 
  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"
    }
  }
}