SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37d970044354dfd7ea17ddd81a7d77b8a4710754d3ad9675e8429743d0b0c779' 
  AND token = 'HCTfBq90R227NtJHDbUUXL+GZT9HzcUc9c8LIYxYxfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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