SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db2ac01eba36c3d862ab8450e7d3f5bb1443293efbf2e008951e58e1d62e013a' 
  AND token = 'KYYywPq/ycjOiOWBSSdYRfvf5HmgFqZUMW9xZxAGstY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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